ABSTRACT This study aims to further develop and test our voice-activated technology to deliver components of cognitive behavioral therapy for insomnia (CBT-I) to breast cancer survivors (BCS). CBT-I is a structured, systematic program which delivers better and safer outcomes than prescription sleep medications. Non-pharmacologic approaches target physiologic, cognitive, behavioral, environmental, and social factors to improve sleep. Insomnia has numerous health consequences, particularly for this high-risk population, and too few trained CBT-I therapists are available to offer treatment. Online programs suffer from high dropout rates and are not appropriate to use ?just-in-time? before sleep (i.e. in the bedroom) due to stimulating screen exposures. Participants will interact with an internet-connected speaker to report sleep patterns and receive feedback, more closely mimicking the experience of an in-person provider than web-based programs. In Aim 1, our multidisciplinary team will invite n=16-20 BCS with insomnia to use the ?Sleep Helper? prototype, collecting data both through participant observation and through week long at home rapid testing. We will use results to iteratively improve the program. We will refine and debug the prototype before conducting our Aim 2, week long at home pilot testing among n=20 BCS to compare sleep data collected by the program with validated self-report and objective measures, and to measure participant engagement and usability of the program. In our final aim we will test the program for efficacy using a randomized controlled trial design with n=58 BCS. We will measure differences between intervention and usual care from baseline to post six-week intervention. Our central hypothesis is that the intervention group will have significantly greater reductions in clinically significant insomnia as recorded by the Insomnia Severity Index. Secondarily, we will measure participant engagement with the program and user satisfaction. This intervention includes engaging and educational elements, and multiple areas of innovation which overcome current impediments to the delivery of scalable, automated CBT-I. We anticipate that the results will demonstrate efficacy of the CBT-I system on insomnia through a randomized controlled trial as well as more feedback on usability and acceptability of the system. Successful completion of Phase II aims will provide evidence to support our commercialization plan to provide this technology to the growing population of BCS with insomnia who lack access to trained CBT-I therapists, as well as to tailor it to other high-risk populations. We also plan to test it as part of a stepped-care model with in-person therapists.